AU2003276289B2

AU2003276289B2 - Elevator cable tensioning device

Info

Publication number: AU2003276289B2
Application number: AU2003276289A
Authority: AU
Inventors: Esko Aulanko; Jorma Mustalahti
Original assignee: Kone Corp
Current assignee: Kone Corp
Priority date: 2002-11-04
Filing date: 2003-11-04
Publication date: 2009-06-04
Anticipated expiration: 2023-11-04
Also published as: ES2329895T3; BR0315803A; EP1567441A1; EA200500553A1; KR20050065671A; HK1081936A1; EP1558513B1; SI1558513T1; NO20051912L; CA2502523A1; BR0315804A; AU2003276290A1; PT1558513E; WO2004041701A1; US20050217944A1; US20050224301A1; CA2502523C; JP4468892B2; MXPA05004782A; JP2006505474A

Abstract

An elevator may include an elevator car, two or more diverting pulleys on the elevator car, one or more hoisting ropes, a traction sheave, and a compensating device. The hoisting ropes may include first, second, third, and fourth rope portions. The first rope portions may extend upward from at least one diverting pulley and the second rope portions may extend downward from at least one diverting pulley. The first rope portions may be under a first tension caused by the compensating device acting on the third rope portion and the second rope portions may be under a second tension caused by the compensating device acting on the fourth rope portion. The first tension to the second rope tension may be maintained substantially constant and may be independent of a load of the elevator.

Description

WO 2004/041699 PCT/F12003/000817 ELEVATOR CABLE TENSIONING DEVICE The present invention relates to an elevator as de fined in the preamble of claim 1 and to a method as defined in the preamble of claim 15. 5 One of the objectives in elevator development work is to achieve efficient and economical utilization of building space. In recent years, this development work has produced various elevator solutions without ma chine room, among other things. Good examples of ele 10 vators without machine room are disclosed in specifi cations EP 0 631 967 (Al) and EP 0 631 968. The eleva tors described in these specifications are fairly ef ficient in respect of space utilization as they have made it possible to eliminate the space required by 15 the elevator machine room in the building without a need to enlarge the elevator shaft. In the elevators disclosed in these specifications, the machine is com pact at least in one direction, but in other direc tions it may have much larger dimensions than a con 20 ventional elevator machine. In these basically good elevator solutions, the space required by the hoisting machine limits the freedom of choice in elevator lay-out solutions. Space is needed for the arrangements required for the passage of the 25 hoisting ropes. It is difficult to reduce the space required by the elevator car itself on its track and likewise the space required by the counterweight, at least at a reasonable cost and without impairing ele vator performance and operational quality. In a trac 30 tion sheave elevator without machine room, mounting the hoisting machine in the elevator shaft is often difficult, especially in a solution with machine above, because the hoisting machine is a sizeable body of considerable weight. Especially in the case of lar 35 ger loads, speeds and/or hoisting heights, the size WO 2004/041699 PCT/F12003/000817 2 and weight of the machine are a problem regarding in stallation, even so much so that the required machine size and weight have in practice limited the sphere of application of the concept of elevator without machine 5 room or at least retarded the introduction of said concept in larger elevators. In modernization of ele vators, the space available in the elevator shaft of ten limits the area of application of the concept of elevator without machine room. In many cases, espe 10 cially when hydraulic elevators are to be modernized or replaced, it is not practical to apply the concept of roped elevator without machine room due to insuffi cient space in the shaft, especially in a case where the hydraulic elevator solution to be modern 15 ized/replaced has no counterweight. A disadvantage with elevators provided with a counterweight is the cost of the counterweight and the space it requires in the shaft. Drum elevators, which are nowadays rarely used, have the drawbacks of heavy and complex hoisting 20 machines with a high power/torque requirement. Prior art elevator solutions without counterweight are ex otic, and no adequate solutions are known. Before, it has not been technically or economically reasonable to make elevators without a counterweight. One solution 25 of this type is disclosed in specification W09806655. A recent elevator solution without counterweight pre sents a viable solution. In prior-art elevator solu tions without counterweight, the tensioning of the hoisting rope is implemented using a weight or spring, 30 and this is not an attractive approach to implementing the tensioning of the hoisting rope. Another problem with elevator solutions without counterweight, when long ropes are used e.g. due to a large hoisting height or a large rope length required by high suspen 35 sion ratios, is the compensation of the elongation of the ropes and the fact that, due to rope elongation, the friction between the traction sheave and the WO 2004/041699 PCT/F12003/000817 3 hoisting ropes is insufficient for the operation of the elevator. In a hydraulic elevator, especially a hydraulic elevator with lifting force applied from be low, the shaft efficiency, in other words the ratio of 5 the cross-sectional shaft area occupied by the eleva tor car to the total cross-sectional area of the ele vator shaft, is fairly high. This has traditionally been a significant factor contributing towards the choice of a hydraulic elevator as the elevator solu 10 tion for a building. On the other hand, hydraulic ele vators have many drawbacks associated with their lift ing mechanism and oil consumption. Hydraulic elevators consume plenty of energy, possible oil leakages from the elevator equipment is an environmental risk, the 15 required periodic oil changes constitute a large cost item, even an elevator installation in good repair produces unpleasant smell as small amounts of oil es cape into the elevator shaft or machine room and from there further into other parts of the building and 20 into the environment and so on. Because of the shaft efficiency of the hydraulic elevator, its moderniza tion by replacement with another type of elevator that would obviate the drawbacks of a hydraulic elevator while necessarily involving the use of a smaller ele 25 vator car is not an attractive solution to the owner of the elevator. Also, the small machine spaces of hy draulic elevators, which may be located at a large distance from the elevator shaft, make it difficult to change the elevator type. 30 There are a very large number of traction sheave ele vators installed and in use. Such traction sheave ele vators were built in their time in accordance with the users' needs as conceived at the time and the intended uses of the buildings in question. Afterwards, both 35 users' needs and the uses of the buildings have changed in many cases, and an old traction sheave ele- WO 2004/041699 PCT/F12003/000817 4 vator may have proved to be insufficient in respect of car size or otherwise. For example, older and rela tively small elevators are not necessarily suited for the transportation of prams or wheelchairs. On the 5 other hand, in older buildings which have been con verted from residential use for office or other uses, a smaller elevator installed in its time is no longer sufficient in respect of capacity. As is known, enlarging such a traction sheave elevator is practi 10 cally impossible because the elevator car and the counterweight already take up the cross-sectional area of the elevator shaft and there is no reasonable way of enlarging the car. The object of the invention in general is to achieve 15 at least one of the following objectives. On the one hand, it is an aim the invention to develop the eleva tor without machine room further so as to allow more effective space utilization in the building and eleva tor shaft than before. This means that the elevator 20 must be so constructed that it can be installed in a fairly narrow elevator shaft if necessary. One objec tive is to achieve an elevator in which the hoisting rope has a good grip/contact on the traction sheave. Yet another objective is to achieve an elevator solu 25 tion without counterweight without compromising the properties of the elevator. A further objective is to eliminate the adverse effects of rope elongations. It is an objective of the invention to create a method for replacing or modernizing a hydraulic elevator 30 with/into a rope-driven elevator without reducing or at least without substantially reducing the size of the elevator car. It is an objective of the invention to enable a rope-driven elevator to be modernized into an elevator with a clearly larger car or to be re 35 placed with an elevator with a larger car than before.

WO 2004/041699 PCT/F12003/000817 5 The object of the invention should be achieved without compromising the possibility of varying the basic ele vator layout. The elevator of the invention is characterized by what 5 is disclosed in the characterization part of claim 1. The method of the invention is characterized by what is disclosed in the characterization part of claim 15. Other embodiments of the invention are characterized by what is disclosed in the other claims. Inventive 10 embodiments are also discussed in the description sec tion of the present application. The inventive content of the application can also be defined differently than in the claims below. The inventive content may also consist of several separate inventions, espe 15 cially if the invention is considered in the light of expressions or implicit sub-tasks or from the point of view of advantages or categories of advantages achieved. Therefore, some of the attributes contained in the claims below may be superfluous from the point 20 of view of separate inventive concepts. For example, the equipment comprising the main components of the elevator to be installed in place of the earlier ele vator, or the equipment designed for modernization of the hoisting system of the earlier elevator, the 25 equipment comprising the machinery, ropes and divert ing pulleys needed for the hoisting function and ac cessories for the installation of these, and possibly also the elevator car and guide rails, is an inventive whole together with an instruction to replace or alter 30 the elevator at least in respect of the hoisting func tion so as to make it consistent with the present ap plication. By applying the invention, one or more of the follow ing advantages, among others, can be achieved: WO 2004/041699 PCT/F12003/000817 6 - Due to a small traction sheave, an elevator and/or elevator machine of a fairly compact size are/is achieved - A good traction sheave grip, which is achieved in 5 particular by using Double Wrap roping, and light weight components allow the weight of the elevator car to be considerably reduced. - A compact machine size and thin, substantially round ropes permit the elevator machine to be rela 10 tively freely placed in the shaft. Thus, the eleva tor solution of the invention can be implemented in a fairly wide variety of ways in the case of both elevators with machine above and elevators with ma chine below. 15 - The elevator machine can be advantageously placed between the car and a shaft wall. - All or at least part of the weight of the elevator car can be carried by the elevator guide rails. - Applying the invention allows effective utilization 20 of the cross-sectional area of the shaft. Thus, e.g. a hydraulic elevator can be modernized into a rope-driven elevator or replaced in the same shaft with a rope-driven elevator without reducing the size of the elevator car, or an old traction sheave 25 elevator can be replaced with or modernized into a larger elevator. - The light, thin ropes are easy to handle, allowing considerably faster installation. - E.g. in elevators for a nominal load below 1000 kg, 30 the thin and strong steel wire ropes of the inven tion have a diameter of the order of only 3-5 mm, although thinner and thicker ropes may also be used. - With rope diameters of about 6 mm or 8 mm, fairly 35 large and fast elevators according to the invention can be achieved. - Either coated or uncoated ropes can be used.

WO 2004/041699 PCT/F12003/000817 7 - The use of a small traction sheave makes it possi ble to use a smaller elevator drive motor, which means a reduction in drive motor acquisi tion/manufacturing costs. 5 - The invention can be applied in gearless and geared elevator motor solutions. - Although the invention is primarily intended for use in elevators without machine room, it can also be applied in elevators with machine room. 10 - In the invention, a better grip and a better con tact between the hoisting ropes and the traction sheave are achieved by increasing the contact angle between them. - Due to the improved grip, the size and weight of 15 the car can be reduced. - The space saving potential of the elevator of the invention is increased considerably as the space required by the counterweight is at least partially eliminated. 20 - As a result of the lighter and smaller elevator system, energy savings and at the same time cost savings are achieved. - The placement of the machine in the shaft can be relatively freely chosen as the space required by 25 the counterweight and counterweight guide rails and roping can be used for other purposes - By mounting at least the elevator hoisting machine, the traction sheave and a rope sheave functioning as a diverting pulley in a complete unit, which is 30 fitted as a part of the elevator of the invention, considerable savings in installation time and costs will be achieved. - In the elevator solution of the invention, it is possible to dispose all ropes in the shaft on one 35 side of the elevator car; for example, in the case of rucksack type solutions, the ropes can be ar ranged to run behind the elevator car in the space WO 2004/041699 PCT/F12003/000817 8 between the elevator car and the back wall of the elevator shaft. - The invention makes it easy to implement scenic type elevator solutions as well. 5 - Since the elevator solution of the invention does not necessarily comprise a counterweight, it is possible to implement elevator solutions in which the elevator car has doors in several walls, in an extreme case even in all the walls of the elevator 10 car. In this case, the car guide rails of the ele vator are disposed at the corners of the elevator car. - The elevator solution of the invention can be im plemented with several different machine solutions. 15 - The suspension of the car can be implemented using almost any suitable suspension ratio. - Compensation of rope elongations by means of a com pensating system according to the invention is a cheap and simple structure to implement. 20 - Compensation of rope elongations by means of a lever is a cheap and light structure. - Using the rope elongation compensation solutions of the invention, it is possible to achieve a constant ratio between the forces T 1

/T

2 acting on the trac 25 tion sheave. - The ratio between the forces T 1

/T

2 acting on the traction sheave is independent of the load. - By using the rope elongation compensating system of the invention, unnecessary stress on the machine and 30 ropes can be avoided. - By using the rope elongation compensating solutions of the invention, the relation between the forces

T

1

/T

2 can be optimized to achieve a desired value. - The solutions of the invention for compensating rope 35 elongation are safe solutions which make it possible to guarantee the required friction / contact between WO 2004/041699 PCT/F12003/000817 9 the traction sheave and the hoisting rope in all situations. - In addition, the rope elongation compensating solu tions of the invention make it unnecessary to stress 5 the hoisting ropes in order to ensure friction be tween the traction sheave and the hoisting rope by loads larger than necessary, and consequently the useful life of the hoisting ropes is increased and their damage susceptibility is reduced. 10 - When rope elongation is compensated using the ar rangement of the invention for compensating rope elongation with compensating sheaves of different diameters, it will be possible using this solution to compensate even very large rope elongations, de 15 pending on the diameters of the pulleys used. - By using a rope elongation compensating solution ac cording to the invention in which the compensating apparatus used is a differential gear, it is possi ble to compensate even large rope elongations, espe 20 cially in the case of high hoisting heights. The primary area of application of the invention is elevators designed for the transportation of people and/or freight. A typical area of application of the invention is in elevators whose speed range is about 25 1.0 m/s or below but may also be higher. For example, an elevator having a traveling speed of 0.6 m/s is easy to implement according to the invention. In both passenger and freight elevators, many of the advantages achieved through the invention are pro 30 nouncedly brought out even in elevators for only 2-4 people, and distinctly already in elevators for 6-8 people (500 - 630 kg). According to the invention, when an elevator, e.g. a hydraulic elevator or traction sheave elevator, is to 35 be modernized or replaced, the existing elevator is WO 2004/041699 PCT/F12003/000817 10 removed partly or completely and a new elevator is formed, wherein the elevator car is suspended on a set of continuous hoisting ropes comprising rope portions going upwards from the elevator car and downwards from 5 the elevator car. The new elevator to be set up is a traction sheave elevator, which is preferably imple mented completely without counterweight. The old hoisting function is always removed from service, preferably also removed physically, which means that, 10 for example in the case of a hydraulic elevator, the hydraulic cylinder and hydraulic machine are removed from the elevator or that, in the case of a traction sheave elevator, the old hoisting ropes, hoisting ma chine and counterweight are removed. The same elevator 15 car or an enlarged or new elevator car is suspended on a new set of hoisting ropes, which can be installed while the old hoisting function is being removed or as a separate installation operation. A hydraulic eleva tor lifted from below or a corresponding hydraulic 20 elevator can be easily converted into a roped elevator without having to reduce the size of the elevator car. When a so-called roped hydraulic elevator is to be re placed or modernized, the invention makes it possible to use a somewhat larger elevator car because, instead 25 of a hydraulic cylinder placed at the side of the ele vator car, only a space for the hoisting ropes is needed. When a traction sheave elevator is to be mod ernized or replaced, the invention already allows a clearly larger elevator car to be used, because the 30 share of the shaft width required for the counter weight and counterweight guide rails, either laterally or towards the back wall, becomes available for accom modating a larger elevator car. Thus, for example, an elevator for 6 persons can be replaced with an eleva 35 tor for 8 persons, or an elevator for 8 persons can be replaced with an elevator for 10 persons. The inven tion is also applicable for use in connection with WO 2004/041699 PCT/F12003/000817 11 larger elevators, although the most suitable range of application is elevators conventionally used in resi dential and office buildings, i.e. elevators designed for a nominal load of about 1000 kg or less. The ele 5 vator modernization or "full replacement" according to the invention is accomplished by replacing or modern izing an elevator installed in an elevator shaft or equivalent, e.g. in a partially open space located at the side of a building yet delimiting the elevator in 10 respect of placement. In general, modernization pri marily means modernizing the hoisting function and secondarily increasing the car size. The motive for modernization may consist of one or both of the above mentioned reasons or some other reason. When an eleva 15 tor is to be replaced, generally the car and the hoisting function are replaced. Heavy modernization of an elevator system or nearly complete replacement of the old elevator system are in many cases mutually al ternative due to economic factors. 20 In the elevator of the invention, normal elevator hoisting ropes, such as generally used steel wire ropes, are applicable. In the elevator, it is possible to use ropes made of artificial materials and ropes in which the load-bearing part is made of artificial fi 25 ber, such as e.g. so-called "aramid ropes", which have recently been proposed for use in elevators. Applica ble solutions also include steel-reinforced flat ropes, especially because they allow a small deflec tion radius. Particularly well applicable in the ele 30 vator of the invention are elevator hoisting ropes twisted e.g. from round and strong wires. From round wires, the rope can be twisted in many ways using wires of different or equal thickness. In ropes well applicable in the invention, the wire thickness is be 35 low 0.4 mm on an average. Well applicable ropes made from strong wires are those in which the average wire WO 2004/041699 PCT/F12003/000817 12 thickness is below 0.3 mm or even below 0.2 mm. For instance, thin-wired and strong 4 mm ropes can be twisted relatively economically from wires such that the mean wire thickness in the finished rope is in the 5 range of 0.15 ... 0.25 mm, while the thinnest wires may have a thickness as small as only about 0.1 mm. Thin rope wires can easily be made very strong. In the in vention, rope wires having a strength greater than about 2000 N/mm2 can be used. A suitable range of rope 10 wire strength is 2300-2700 N/mm 2 . In principle, it is possible to use rope wires having a strength of up to about 3000 N/mm 2 or even more. The elevator of the invention, in which the elevator car is suspended by means of hoisting ropes consisting 15 of a single rope or a number of parallel ropes, said elevator having a traction sheave which moves the ele vator car by means of the hoisting ropes, has rope portions of the hoisting ropes going upwards and down wards from the elevator car, and the rope portions go 20 ing upwards from the elevator car are under a first rope tension (T1) which is greater than a second rope tension (T 2 ), which is the rope tension of the rope portions going downwards from the elevator car. In ad dition, the elevator comprises a compensating system 25 for keeping the ratio (T 1

/T

2 ) between the first rope tension and the second rope tension substantially con stant. In the method of the invention for forming an eleva tor, the elevator car is connected to the elevator 30 roping used to hoist the elevator car, said roping consisting of a single rope or a plurality of parallel ropes and comprising rope portions going upwards and downwards from the elevator car, and that the elevator roping is provided with a compensating system for 35 keeping the ratio (T 1

/T

2 ) between the rope forces act- WO 2004/041699 PCT/F12003/000817 13 ing in upward and downward directions substantially constant. By increasing the contact angle by means of a rope sheave functioning as a diverting pulley, the grip be 5 tween the traction sheave and the hoisting ropes can be increased. In this way, the car can be made lighter and its size can be reduced, thus increasing the space saving potential of the elevator. A contact angle of over 1800 between the traction sheave and the hoisting 10 rope is achieved by using one or more diverting pul leys. The need to compensate the rope elongation arises from the friction requirements, to ensure that a grip sufficient for operation and safety of the ele vator exists between the hoisting rope and the trac 15 tion sheave. On the other hand, it is essential in re spect of elevator operation and safety that the rope portion below the elevator car in an elevator solution without counterweight should be kept sufficiently tight. This can not necessarily be achieved using a 20 spring or a simple lever. In the following, the invention will be described in detail by the aid of a few examples of its embodiments with reference to the attached drawings, wherein Fig. 1 is a diagram representing a traction sheave 25 elevator without counterweight according to the invention Fig. 2 presents diagram of another traction sheave elevator without counterweight according to the invention, 30 Fig. 3 presents a diagram of a third traction sheave elevator without counterweight according to the invention, Fig. 4 presents a diagram of a fourth traction sheave elevator without counterweight accord 35 ing to the invention, WO 2004/041699 PCT/F12003/000817 14 Fig. 5 presents a diagram of another traction sheave elevator without counterweight according to the invention, Fig. 6 presents a diagram of another traction sheave 5 elevator without counterweight according to the invention, Fig. 7 presents a diagram of another traction sheave elevator without counterweight according to the invention, 10 Fig. 8 presents a diagram of another traction sheave elevator without counterweight according to the invention, Fig. 9 presents a diagram of another traction sheave elevator without counterweight according to 15 the invention, Figures 10 present solutions in which an earlier ele vator layout has been replaced with a solu tion according to the invention. Fig. 1 presents a diagrammatic illustration of the 20 structure of an elevator according to the invention. The elevator is preferably an elevator without machine room, with a drive machine 4 placed in an elevator shaft. The elevator shown in the figure is a traction sheave elevator without counterweight and with machine 25 above. The passage of the hoisting ropes 3 of the ele vator is as follows: One end of the ropes is immovably fixed to a fixing point 16 on a lever 15 fastened to the elevator car 1, said fixing point being located at a distance a from the pivot 17 connecting the lever to 30 the elevator car 1. In Fig. 1, the lever 15 is thus pivoted on the elevator car 1 at fixing point 17. From fixing point 16, the hoisting ropes 3 run upwards to a diverting pulley 14 placed in the upper part of the elevator shaft above the elevator car 1, from which 35 diverting pulley the ropes 3 go further downwards to a diverting pulley 13 on the elevator car, and from this WO 2004/041699 PCT/F12003/000817 15 diverting pulley 13 the ropes go upwards again to a diverting pulley 12 fitted in the upper part of the shaft above the car. From diverting pulley 12, the ropes go further downwards to a diverting pulley 11 5 mounted on the elevator car. Having passed around this pulley, the ropes go again upwards to a diverting pul ley 10 fitted in the upper part of the shaft, and hav ing passed around this pulley they go downwards again to a diverting pulley 9 fitted on the elevator car. 10 After wrapping around this diverting pulley 9, the hoisting ropes 3 go further upwards to the traction sheave 5 of the drive machine 4 placed in the upper part of the elevator shaft, having previously passed via a diverting pulley 7 with only a "tangential con 15 tact" with the ropes. This means that the ropes 3 go ing from the traction sheave 5 to the elevator car 1 pass via the rope grooves of diverting pulley 7 while the deflection of the rope 3 caused by the diverting pulley 7 is very small. It could be said that the 20 ropes 3 coming from the traction sheave 5 only touch the diverting pulley 7 "tangentially". Such "tangen tial contact" serves as a solution damping the vibra tions of the outgoing ropes and it can be applied in other roping solutions as well. The ropes pass around 25 the traction sheave 5 of the hoisting machine 4 along the rope grooves of the traction sheave 5. From the traction sheave 5, the ropes 3 go further downwards to diverting pulley 7, passing around it along the rope grooves of the diverting pulley 7 and returning back 30 up to the traction sheave 5, over which they pass along the rope grooves of the traction sheave. From the traction sheave 5, the hoisting ropes 3 go further downwards in "tangential contact" with diverting pul ley 7 past the elevator car 1 moving along guide rails 35 2, to a diverting pulley 8 placed in the lower part of the elevator shaft, passing around it along the rope grooves on it. From the diverting pulley 8 in the WO 2004/041699 PCT/F12003/000817 16 lower part of the elevator shaft, the ropes go upwards to a diverting pulley 18 on the elevator car, from where the ropes 3 go further to a diverting pulley 19 in the lower part of the elevator shaft and further 5 back up to a diverting pulley 20 on the elevator car, from where the ropes 3 go further downwards to a di verting pulley 21 in the lower part of the shaft, from where they go further to a diverting pulley 22 on the elevator car, from where the ropes 3 go further to a 10 diverting pulley 23 in the lower part of the elevator shaft. From diverting pulley 23, the ropes 3 go fur ther to the lever 15 pivotally fixed to the elevator car 1 at point 17, one end of the ropes 3 being im movably fastened to said lever 15 at point 24 at dis 15 tance b from the pivot 17. In the case illustrated in Fig. 1, the hoisting machine and the diverting pulleys are preferably all placed on one and the same side of the elevator car. This solution is particularly advan tageous in the case of a rucksack-type elevator, in 20 which case the above-mentioned components are disposed behind the elevator car, in the space between the ele vator car and the back wall of the shaft. The hoisting machine and the diverting pulleys may also be laid out in other appropriate ways in the elevator shaft. The 25 roping arrangement between the traction sheave 5 and the diverting pulley 7 is referred to as Double Wrap roping, wherein the hoisting ropes are wrapped around the traction sheave two and/or more times. In this way, the contact angle can be increased in two and/or 30 more stages. For example, in the embodiment presented in Fig. 1, a contact angle of 1800 + 1800, i.e. 360 between the traction sheave 5 and the hoisting ropes 3 is achieved. The Double Wrap roping presented in the figure can also be arranged in another way, e.g. by 35 placing diverting pulley 7 on the side of the traction sheave 5, in which case, as the hoisting ropes pass twice around the traction sheave, a contact angle of WO 2004/041699 PCT/F12003/000817 17 1800 + 900, i.e. 2700 is achieved, or by placing the traction sheave in some other appropriate location. A preferable solution is to dispose the traction sheave 5 and the diverting pulley 7 in such a way that the 5 diverting pulley 7 will also function as a guide of the hoisting ropes 3 and as a damping pulley. Another advantageous solution is to build a complete unit com prising both an elevator drive machine with a traction sheave and one or more diverting pulleys with bearings 10 in a correct operating angle relative to the traction sheave. The operating angle is determined by the rop ing used between the traction sheave an the diverting pulley/diverting pulleys, which defines the way in which the mutual positions and angle between the trac 15 tion sheave and diverting pulley/diverting pulleys relative to each other are fitted in the unit. This unit can be mounted in place as a unitary aggregate in the same way as a drive machine. In a preferred case, the drive machine 4 may be fixed e.g. to a car guide 20 rail, and the diverting pulleys 7,10,12,14 in the up per part of the shaft are mounted on the beams in the upper part of the shaft, which are fastened to the car guide rails 2. The diverting pulleys 9,11,13,18,20,22 on the elevator car are preferably mounted on beams 25 disposed in the upper and lower parts of the car, but they may also be secured to the car in other ways, e.g. by mounting all the diverting pulleys on the same beam. The diverting pulleys 8,19,21,23 in the lower part of the shaft are preferably mounted on the shaft 30 floor. In Fig. 1, the traction sheave engages the rope portion between diverting pulleys 8 and 9, which is a preferable solution according to the invention. In a preferable solution according to the invention, the elevator car 1 is connected to the hoisting ropes 3 by 35 means of at least one diverting pulley from the rim of which the hoisting ropes go upwards from both sides of the diverting pulley, and at least one diverting pul- WO 2004/041699 PCT/F12003/000817 18 ley from the rim of which the hoisting ropes go down wards from both sides of the diverting pulley, and in which elevator the traction sheave 5 engages the por tion of the hoisting rope 3 between these diverting 5 pulleys. The roping between the traction sheave 5 and diverting pulley 7 can also be implemented in other ways instead of Double Wrap roping, such as e.g. by using Single Wrap roping, in which case diverting pul ley 7 will not necessarily be needed at all, ESW rop 10 ing (Extended Single Wrap), XW roping (X wrap) or some other appropriate roping solution. The drive machine 4 placed in the elevator shaft is preferably of a flat construction, in other words, the machine has a small thickness dimension as compared to 15 its width and/or height, or at least the machine is slim enough to be accommodated between the elevator car and a wall of the elevator shaft. The machine may also be placed differently, e.g. by disposing the slim machine partly or completely between an imaginary ex 20 tension of the elevator car and a shaft wall. In the elevator of the invention, it is possible to use a drive machine 4 of almost any type and design that fits into the space intended for it. For example, it is possible to use a geared or gearless machine. The 25 machine may be of a compact and/or flat size. In the suspension solutions according to the invention, the rope speed is often high as compared to the speed of the elevator, so it is possible to use even unsophis ticated machine types as the basic machine solution. 30 The elevator shaft is advantageously provided with equipment required for the supply of power to the mo tor driving the traction sheave 5 as well as equipment needed for elevator control, both of which can be placed in a common instrument panel 6 or mounted sepa 35 rately from each other or integrated partly or wholly with the drive machine 4. A preferable solution is a WO 2004/041699 PCT/F12003/000817 19 gearless machine comprising a permanent magnet motor. The drive machine may be fixed to a wall of the eleva tor shaft, to the ceiling, to a guide rail or to some other structure, such as a beam or frame. In the case 5 of an elevator with machine below, a further possibil ity is to mount the machine on the bottom of the ele vator shaft. Fig. 1 illustrates a preferred suspension solution in which the suspension ratio of the divert ing pulleys above the elevator car and the diverting 10 pulleys below the elevator car is the same 7:1 suspen sion in both cases. To visualize this ratio in prac tice, it means the ratio of the distance traveled by the hoisting rope to the distance traveled by the ele vator car. The suspension arrangement above the eleva 15 tor car I is implemented by means of diverting pulleys 14,13,12,11,10,9 and the suspension arrangement below the elevator car 1 is implemented by means of divert ing pulleys 23,22,21,20,19,18,8. Other suspension so lutions can also be used to implement the invention. 20 The elevator of the invention can also be implemented as a solution comprising a machine room, or the ma chine may be mounted to be movable together with the elevator. In the invention, the diverting pulleys con nected to the elevator car may be preferably mounted 25 on one and the same beam. This beam may be fitted on top of the car, on the side of the car or below the car, on the car frame or in some other appropriate place in the car structure. The diverting pulleys may also be fitted each one separately in appropriate 30 places on the car and in the shaft. The diverting pul leys placed above the elevator car in the elevator shaft, preferably in the upper part of the elevator shaft, and/or the diverting pulleys placed below the elevator car in the elevator shaft, preferably in the 35 lower part of the elevator shaft, may also be fitted e.g. on a common anchorage, such as e.g. a beam.

WO 2004/041699 PCT/F12003/000817 20 The function of the lever 15 pivoted on the elevator car at point 17 in Fig. 1 is to eliminate rope elonga tions occurring in the hoisting rope 3. On the other hand, it is essential to the operation and safety of 5 the elevator that a sufficient tension be maintained in the lower rope portion, which refers to that part of the hoisting rope which is below the elevator car. By means of the lever arrangement 15 according to the invention, the tensioning of the hoisting rope and the 10 compensation of rope elongation can be achieved with out using a prior-art spring or weight. By means of the lever arrangement 15 of the invention, it is also possible to implement the rope tensioning in such man ner that the ratio TI/T 2 between the rope forces T, and 15 T 2 acting in different directions on the traction sheave 5 can be kept at a desired constant value, which may be e.g. 2. In connection with rope forces, we can also speak of rope tensions. This constant ra tio can be varied by varying the distances a and b, 20 because Ti/T 2 = b/a. When odd suspension ratios are used in the suspension of the elevator car, the lever 15 is pivoted on the elevator car, and when even sus pension ratios are used, the lever 15 is pivoted on the elevator shaft. 25 Fig. 2 presents a diagrammatic illustration of the structure of an elevator according to the invention. The elevator is preferably an elevator without machine room, with the drive machine 204 placed in the eleva tor shaft. The elevator shown in the figure is a trac 30 tion sheave elevator with machine above and without counterweight, with an elevator car 201 moving along guide rails 2. The passage of the hoisting ropes 203 in Fig. 2 is similar to that in Fig. 1, but in Fig. 2 there is the difference that the lever 215 is immova 35 bly pivoted on a wall of the elevator shaft at point 217. As the lever 215 is pivoted on the elevator WO 2004/041699 PCT/F12003/000817 21 shaft, preferably on a wall of the elevator shaft, in stead of on the elevator car, this is a case of even suspension ratio both in the rope portion above the elevator car 1 and in the rope portion below it. The 5 suspension above the elevator car comprises the hoist ing machine 204 and diverting pulleys 209,210,211,212,213,214. The suspension below the ele vator car comprises diverting pulleys 208,218,219, 229,221,222,223. One end of the hoisting rope is fas 10 tened to the lever 215 at point 216, which is at dis tance a from the pivot 217, while its other end is fastened to the lever 215 at point 224, which is at distance b from the pivot 217. Both in the rope por tion above the elevator car and in the rope portion 15 below it, the suspension ratio of the elevator car is 6:1. Due to a high suspension ratio, the rope length of the hoisting rope used in an elevator without 'counter weight is large. For example, in an elevator without 20 counterweight suspended with a suspension ratio of 10:1, in which the same suspension ratio 10:1 is used both above and below the elevator car, and which ele vator has a hoisting height of 25 meters, the rope length of the hoisting rope is about 270 meters. In 25 this case, as a result of variations in rope stress and/or temperature, the length of the rope may change by as much as about 50 cm. Therefore, the requirements regarding compensation of rope elongation are also greater. For the operation and safety of the elevator, 30 it is essential that the rope below the elevator car be kept under a sufficient tension. This can not al ways be accomplished by using a spring or a simple lever. Fig. 3 presents a diagrammatic illustration of the 35 structure of an elevator according to the invention.

WO 2004/041699 PCT/F12003/000817 22 The elevator is preferably an elevator without machine room, with the drive machine 304 placed in the eleva tor shaft. The elevator shown in the figure is a trac tion sheave elevator with machine above and without 5 counterweight, with an elevator car 301 moving along guide rails 302. In Fig. 3, the lever solution used in Fig. 1 and 2 has been replaced with two sheave-like bodies, preferably sheaves 313 and 315, connected to each other at point 314, where the tensioning sheaves 10 313,315 are fixedly secured to the elevator car 301. Of the sheave-like bodies, the sheave 315 engaging the hoisting rope portion below the elevator car has a di ameter larger than the diameter of the sheave 313 en gaging the hoisting rope portion above the elevator 15 car. The diameter ratio between the diameters of the tensioning sheaves 313 and 315 determines the magni tude of the tensioning force acting on the hoisting rope and therefore also the force of compensation of hoisting rope elongations. In this solution, the use 20 of tensioning sheaves provides the advantage that the structure compensates even very large rope elonga tions. By varying the diametric size of the tensioning sheaves, it is possible to influence the magnitude of the rope elongation to be compensated and the ratio 25 between the rope forces T 1 and T 2 acting on the trac tion sheave, which ratio can be rendered constant by this arrangement. Due to a large suspension ratio or a large hoisting height, the length of the rope used in the elevator is large. For the operation and safety of 30 the elevator, it is essential that the hoisting rope portion below the elevator car be kept under a suffi cient tension and that the amount of rope elongation to be compensated be large. Often this can not be im plemented using a spring or a simple lever. With odd 35 suspension ratios above and below the elevator car, the tensioning sheaves are immovably fitted in connec tion with the elevator car, and with even suspension WO 2004/041699 PCT/F12003/000817 23 ratios the tensioning sheaves are immovably fitted to the elevator shaft or some other corresponding loca tion which is not fixedly fitted to the elevator car. The solution can be implemented using tensioning 5 sheaves as presented in Fig. 3 and 4, but the number of sheave-like bodies used may vary; for example, it is possible to use only one sheave with locations fit ted for hoisting rope fixing points differing in di ameter. It is also possible to use more than two ten 10 sioning sheaves e.g. to allow the diameter ratio be tween the sheaves to be varied by only changing the diameter of the tensioning sheaves. In Fig. 3, the hoisting ropes run as follows. One end of the hoisting ropes is secured to tensioning sheave 15 313, which sheave is immovably attached to sheave 315. This set of sheaves 313,315 is fitted to the elevator car at point 314. From sheave 313, the hoisting ropes 303 go upwards and encounter a diverting pulley 312 placed above the elevator car in the elevator car, 20 preferably in the upper part of the elevator shaft, passing around it along rope grooves provided in the diverting pulley 312. These rope grooves may be coated or uncoated, e.g. with friction increasing material, such as polyurethane or some other appropriate mate 25 rial. From pulley 312, the ropes go further downwards to a diverting pulley 311 on the elevator car, and having passed around this pulley, the ropes go further upwards to a diverting pulley 310 fitted in the upper part of the shaft. Having passed around this diverting 30 pulley 310, the rope goes again downwards to a divert ing pulley 309 mounted on the elevator car, and having passed around this pulley the hoisting ropes go fur ther upwards to a diverting pulley 307 preferably fit ted near the hoisting machine 304. Between diverting 35 pulley 307 and the traction sheave 304, the figure shows X wrap roping, in which roping the hoisting rope WO 2004/041699 PCT/F12003/000817 24 runs crosswise with the rope portion going upwards from diverting pulley 307 to the traction sheave 305 and with the rope portion returning from the traction sheave 305 to diverting pulley 307. Pulleys 5 313,312,311,310,309 together with the hoisting machine form the suspension arrangement above the elevator car, where the suspension ratio is the same as in the suspension arrangement below the elevator car, this suspension ratio being 5:1 in Fig. 3. From diverting 10 pulley 307, the ropes run further to a diverting pul ley 308 preferably fitted in place in the lower part of the elevator shaft e.g. on a car guide rail 302 or on the shaft floor or in some other appropriate place. Having passed around diverting pulley 308, the hoist 15 ing ropes 303 go further upwards to a diverting pulley 316 fitted in place on the elevator car, pass around this pulley and then go further downwards to a divert ing pulley 317 in the lower part of the elevator shaft, passing around it and returning to a diverting 20 pulley 318 fitted in place on the elevator car. Having passed around diverting pulley 318, the hoisting ropes 303 go further downwards to a diverting pulley 319 fitted in place in the lower part of the elevator shaft, passing around it and then going further up 25 wards to the tensioning sheave 315 fitted in place on the elevator car and immovably fitted to tensioning sheave 313. Fig. 4 presents a diagrammatic illustration of the structure of an elevator according to the invention. 30 The elevator is preferably an elevator without machine room, with a drive machine 404 placed in the elevator shaft. The elevator shown in the figure is a traction sheave elevator without counterweight and with machine above, with an elevator car 401 moving along guide 35 rails 402. The passage of the hoisting ropes 403 in Fig. 4 corresponds to that in Fig. 3 with the differ- WO 2004/041699 PCT/F12003/000817 25 ence that in Fig. 4 the tensioning sheaves 413,415 are fitted in place in the elevator shaft, preferably on the bottom of the elevator shaft. As the tensioning sheaves 413,415 are fitted in place in the elevator 5 shaft and not in connection with the elevator car, this is a case of even suspension ratio both in the rope portion above the elevator car 1 and in the rope portion below it. In Fig. 4, the suspension ratio is 4:1. The end of the hoisting ropes 403 below the ele 10 vator car 401 is fastened to the tensioning sheave 415 with a larger diameter while the end of the hoisting ropes above the elevator car is fastened to the ten sioning sheave 413 with a smaller diameter. The ten sioning sheaves 413,415 are immovably fitted together 15 and they are secured to the elevator shaft via a mounting piece 420. The suspension above the elevator car comprises the hoisting machine and diverting pul leys 412,411,410,409,407. The suspension below the elevator car comprises diverting pulleys 20 408,416,417,418,419. A set of tensioning sheaves (415, 413) as illustrated in Fig. 4 used as a compensating system can also be advantageously mounted in place of either diverting pulley 419 at the bottom of the shaft, which pulley is preferably secured to the shaft 25 floor, or diverting pulley 412 in the upper part of the shaft, which pulley is preferably secured to the ceiling of the shaft. In this case, the number of di verting pulleys needed is one less than in the embodi ment presented in Fig. 4. Thus, in advantageous cases, 30 installing the elevator is also an easier and faster operation. Fig. 5 presents a diagrammatic illustration of the structure of an elevator according to the invention. The elevator is preferably an elevator without machine 35 room, with a drive machine 504 placed in the elevator shaft. The elevator presented in the figure is a trac- WO 2004/041699 PCT/F12003/000817 26 tion sheave elevator without counterweight and with machine above, with an elevator car 501 moving along guide rails 502. In elevators with a large hoisting height, the elongation of the hoisting rope involves a 5 need to compensate the rope elongation, which has to be done reliably within certain allowed limit values. Using a set of rope force compensating sheaves 524 ac cording to the invention as presented in Fig. 5, a very long movement is achieved for the compensation of 10 rope elongation. This permits the compensation of even large elongations, which often can not be achieved us ing simple lever or spring solutions. The compensating sheave arrangement according to the invention pre sented in Fig. 5 produces a constant ratio T 1

/T

2 be 15 tween the rope forces T 1 and T 2 acting on the traction sheave. In the case illustrated in Fig. 5, the ratio

T

1

/T

2 equals 2/1. The passage of the hoisting ropes in Fig. 5 is as fol lows. One end of the hoisting ropes 503 is fastened to 20 diverting pulley 525, which diverting pulley has been fitted to hang on the rope portion coming downwards from diverting pulley 514. Diverting pulleys 514 and 525 together form a rope force compensating system 524, which in the case of Fig. 5 is a set of compen 25 sating sheaves. From diverting pulley 514, the hoist ing ropes run further as described in connection with the previous figures between diverting pulleys 512,510,507 fitted in place in the upper part of the elevator shaft and diverting pulleys 513,511,509 fit 30 ted in place on the elevator car, forming the suspen sion arrangement above the elevator car. Between the hoisting machine 504 and the traction sheave 505, DW suspension is used, which was already described in de tail in connection with Fig. 1. The roping between the 35 diverting pulley 507 and the traction sheave can also be implemented using other appropriate roping solu- WO 2004/041699 PCT/F12003/000817 27 tions, such as e.g. SW, XW or ESW suspension. From the traction sheave, the hoisting ropes go further via di verting pulley 507 to a diverting pulley 508 placed in the lower part of the elevator shaft. Having passed 5 around diverting pulley 508, the hoisting ropes run between diverting pulleys 518,520,522 fitted in place in the lower part of the shaft and diverting pulleys 519,521,523 fitted on the elevator car 501 in the man ner described in connection with the previous figures. 10 From diverting pulley 523, the hoisting ropes 503 go further to a diverting pulley 525 comprised in the rope force compensating sheave system 524 and fastened to one end of the hoisting rope. Having passed around diverting pulley 525 along its rope grooves, going 15 further to the anchorage 526 of the other end of the rope in the elevator shaft or in some other appropri ate place. The suspension ratio of the elevator car both above and below the elevator car is 6:1. In the embodiment presented in Fig. 5, the rope force 20 compensating sheave system 524 compensates rope elon gations by means of diverting pulley 525. This divert ing pulley 525 moves through distance I, compensating elongations of the hoisting ropes 503. The compensat ing distance I equals half the rope elongation of the 25 hoisting ropes. In addition, this arrangement produces a constant tension across the traction sheave 505, the ratio T 1

/T

2 between the rope forces being 2/1. The rope force compensating sheave system 524 can also be im plemented in other ways besides that described in the 30 example, e.g. by using more complex suspension ar rangements with the rope force compensating sheaves, for example by using different suspension ratios be tween the diverting pulleys in the compensating sheave system.

WO 2004/041699 PCT/F12003/000817 28 Fig. 6 presents another implementation for the compen sation of rope elongations using a compensating device. In Fig. 6, the passage of the ropes and the suspension ratio in the portions above and below the elevator car 5 are identical to those in Fig. 5 as described above. The hoisting ropes 603 run between diverting pulleys 609,611,613 mounted on the elevator car and diverting pulleys 610,612,614 in the upper part of the elevator shaft and the traction sheave 605 in the manner pre 10 sented in Fig. 5, and the ropes go further from the traction sheave 605 to the lower part of the elevator shaft to traction sheave 608, and having passed around it they run further between the diverting pulleys 618,620,622 fitted on the elevator car and the divert 15 ing pulleys 619,621,623 fitted in the lower part of the elevator shaft as described in connection with Fig. 5. The suspension ratio of the elevator car in the por tions above and below the elevator car is 6:1. The ele vator presented in Fig. 6 differs from the situation 20 illustrated in Fig. 5 in respect of the compensating device 624. Fig. 6 presents a different roping arrange ment according to the invention in the set of compen sating sheaves 624 of the compensating device. In the set of compensating sheaves, one end 629 of the hoist 25 ing ropes 603 is immovably fitted to the elevator shaft, from which point the hoisting ropes go to the traction sheave 625, pass around it and go further to a diverting pulley 614 possibly fitted in place in the upper part of the elevator shaft, from where they run 30 further in the manner described above to the traction sheave 605. Diverting pulley 625 is fixedly fitted in conjunction with another diverting pulley 626. These diverting pulleys 626,625 may be placed e.g. on the same shaft or they may be connected to each other by a 35 bar or in some other appropriate manner. After passing around diverting pulley 623, the portion of the hoist ing ropes 603 below the elevator car comes to the di- WO 2004/041699 PCT/F12003/000817 29 verting pulley 626 of the compensating device 624, this pulley being connected to diverting pulley 625 in the manner described above. Having passed around diverting pulley 626, the hoisting ropes 603 go further to a di 5 verting pulley 627 immovably fitted in place in the shaft and forming part of the compensating system 624. Having passed around the diverting pulley 627, the hoisting ropes 603 go further to an anchorage 628, to which the other end of the hoisting ropes is immovably 10 secured. This anchorage 628 is on diverting pulley 625 or fixedly connected to it. Using this roping arrange ment in the compensating device 624, a constant ratio T1/T2 = 3/2 between the rope forces T, and T 2 is achieved. Using this roping arrangement, it is possible 15 to implement SW roping on the traction sheave, in other words, the diverting pulley 507 shown in Fig. 5 is not necessarily needed at all. SW roping can be used on the traction sheave because the illustrated roping arrange ment in the compensating device 624 minimizes the re 20 quired friction force on the traction sheave and per mits small rope forces T, and T 2 . However, the diverting pulley 507 presented in Fig. 5 can be used if desirable e.g. to provide a tangential contact with the hoisting ropes as described in connection with the previous fig 25 ures. In the compensating device 624, the roping and the number of diverting pulleys may also vary in ways other than those described in this Fig. 6. Via the rop ing suspension ratios in the compensating device 624, the Ti/T 2 ratio can be maintained at a desired constant 30 magnitude. In Fig. 6, the compensation of rope elonga tion is effected by means of diverting pulley 625 and the diverting pulley 626 fixedly fitted to it. The rope elongation compensating distance in the compensating device is the shorter the greater is the suspension ra 35 tio within it.

WO 2004/041699 PCT/F12003/000817 30 Fig. 7 presents an embodiment of the invention in which the suspension ratio of the roping is 1:1. In the ele vator presented in Fig. 7, the compensation of rope elongation is implemented using a lever 715, which 5 lever 715 functions as a rope force compensating device and is immovably pivoted on the elevator car 701. The rope forces are compensated and a constant ratio be tween the rope forces T, and T 2 is achieved in the man ner described in connection with Fig. 1, which yields 10 the T 1

/T

2 ratio as T1/T 2 = b/a, which is independent of the magnitude of the load. The example of an embodiment of the elevator of the invention presented in Fig. 7 can be implemented using e.g. commonly used conven tional ropes having a diameter of 8 mm in an elevator 15 for a nominal load of 4 persons, i.e. about 700 kg. In this elevator, the T 1

/T

2 ratio is 1.5/1 and it uses a traction sheave having a diameter of 320 mm and conven tional undercut grooves, and the mass of the elevator car is 700 kg. In this case, the force Ti lifting the 20 elevator car upwards is 1.5 times the force required for lifting the weight of the elevator car and its load, and the force T 2 acting downwards on the elevator car is the force required for lifting the weight of the elevator car and the load. This example is not ideal as 25 it leads to an unnecessarily high rope tension relative to the load. By increasing the suspension ratio, it is possible to reduce this rope tension. The elevator of the invention may be provided with a geared machine and it can be constructed e.g. according to Fig. 7 with 1:1 30 roping. Fig. 8 presents an elevator according to the invention in which a suspension ratio of 2:1 is used in the rop ing portion 803 of the hoisting ropes above and below the elevator car 801 and DW roping between the traction 35 sheave 805 and the diverting pulley 807. Compensation of rope elongations and constant rope forces are imple- WO 2004/041699 PCT/F12003/000817 31 mented using a rope elongation compensating device as presented in Fig. 5, which produces a rope force ratio of T 1

/T

2 = 2/1 while the compensating distance traveled by the diverting pulley 825 equals half the magnitude 5 of the rope elongation. Fig. 9 presents an embodiment of the invention for com pensating rope elongations and maintaining a constant rope fore ratio. In Fig. 9, the passage of the hoisting ropes is as described above in connection with Fig. 6, 10 where the suspension ratio of the elevator car above and below the elevator car is 6:1. The passage of the hoisting ropes in Fig. 9 differs from the situation shown in Fig. 6 in that the ropes go downwards from di verting pulley 914 to diverting pulley 924, and also in 15 respect of the compensating system. In addition, one end of the hoisting ropes 903 is immovably fixed to the elevator shaft at point 923 before the ropes go to di verting pulley 922. In this figure, the compensation of rope elongation is implemented by fastening diverting 20 pulley 908 to the second end of the hoisting ropes 903 at point 926. The elongation of the hoisting ropes is compensated by allowing diverting pulley 908 to move upwards or downwards through a distance equal to half the rope elongation, thus compensating the rope elonga 25 tion. In the system illustrated in Fig. 9, the compen sation of rope elongations and a constant ratio of rope forces are implemented on the same principle as in the situation represented by Fig. 5, where the rope force ratio is Ti/T 2 and the compensating distance through 30 which diverting pulley 908 moves equals half the magni tude of the rope elongation. The compensating system presented in Fig. 9 can be implemented by means of any one of the diverting pulleys 908,919,921 in the lower part of the elevator shaft by fastening the second end 35 of the hoisting ropes to the diverting pulley in ques- WO 2004/041699 PCT/F12003/000817 32 tion, as described above in connection with diverting pulley 908. When the elevator car is suspended with a small suspen sion ratio, such as e.g. 1:1, 1:2, 1:3 or 1:4, divert 5 ing pulleys of a large diameter and hoisting ropes of a large thickness can be used. Below the elevator car it is possible to use smaller diverting pulleys if neces sary, because the tension in the hoisting ropes is lower than in the portion above the elevator car, al 10 lowing smaller hoisting rope deflection radiuses to be used. In elevators with a small space below the eleva tor car, it is advantageous to use diverting pulleys of small diameter in the rope portion below the elevator car. Since by using the rope force compensating system 15 of the invention a constant tension in the hoisting rope portion below the elevator car can be achieved that is smaller by the ratio Ti/T 2 than the tension in the rope portion above the elevator car, this makes it possible to reduce the diameters of the diverting pul 20 leys in the rope portion below the elevator car without substantially impairing the service life of the hoist ing ropes. For example, the ratio between the diameter D of the diverting pulley to the diameter d of the rope used may be D/d < 40, and preferably this D/d ratio may 25 be only D/d = 25...30, while the ratio of the diameters of the hoisting rope portion and diverting pulleys above the elevator car is D/d = 40. The use of divert ing pulleys of a smaller diameter allows the space be low the elevator car to be reduced to a very small 30 size, which may preferably be only 200 mm. A preferred embodiment of the elevator of the invention is an elevator without machine room and with machine above, in which the drive machine has a coated traction sheave, and which elevator has thin hoisting ropes of a 35 substantially round cross-section. In the elevator, the WO 2004/041699 PCT/F12003/000817 33 contact angle between the hoisting ropes and the trac tion sheave is greater than 1800. The elevator com prises a unit with a mounting base on which are fitted a drive machine, a traction sheave and a diverting 5 pulley ready fitted at a correct angle relative to the traction sheave. The unit is secured to the elevator guide rails. The elevator is implemented without coun terweight with a suspension ratio of 9:1 so that both the roping suspension ratio above the elevator car and 10 the roping suspension ratio below the elevator car is 9:1, and that the roping of the elevator runs in the space between one of the walls of the elevator car and the wall of the elevator shaft. The solution for com pensating the rope elongations of the elevator rope 15 comprises a set of compensating sheaves, which creates a constant ratio TI/T 2 =2:1 between the forces T 1 and T 2 . With the compensating sheave system used, the required compensating distance equals half the magnitude of the rope elongation. 20 Another preferred embodiment of the elevator of the invention is an elevator without counterweight in which the suspension ratio above and below the eleva tor car is 10:1. In this embodiment, conventional ele vator hoisting ropes are used, which preferably are 25 ropes of a diameter of 8 mm, and a traction sheave which is made of cast iron at least in the area of the rope grooves. The traction sheave has undercut rope grooves and a diverting pulley is used to adjust the rope contact on the traction sheave to 1800 or more. 30 When conventional 8-mm ropes are used, the traction sheave diameter is preferably 340 mm. The diverting pulleys used are large rope sheaves which, when con ventional 8-mm hoisting ropes are used, have a diame ter of 320,330,340 mm or even more. The rope forces 35 are kept constant so that the ratio T 1

/T

2 between them is 3/2.

WO 2004/041699 PCT/F12003/000817 34 Fig. 10a and 10b present another example situation, in which a roped elevator with counterweight as shown in Fig. 10a has been replaced with or modernized into a roped elevator without counterweight according to the 5 invention as presented in Fig. 10b. The elevator pre sented in Fig. 10a is a roped elevator with a counter weight 1003, in which elevator the counterweight 1003 and the counterweight guide rails 1004 are placed, as seen from the door opening 1006, behind the elevator 10 car 1001 moving along guide rails 1002, in the eleva tor shaft 1007 in the space between the elevator car 1001 and the shaft wall 1005. Fig. 10b shows how the space required by the counterweight 1003 and its guide rails 1004 has been eliminated in the elevator shaft 15 1007 and how the space thus freed up can be utilized for the elevator car 1001 if necessary. This provides the possibility to install a larger elevator car in the same shaft. In the case of a conventional passen ger elevator as illustrated in Fig. 10b, it is possi 20 ble to obtain e.g. about 20 - 25 cm or even more of additional car depth when the elevator presented in Fig. 10a is replaced with or modernized into an eleva tor without counterweight as shown in Fig. 10b. Fig. 10c and 10d present another example situation, in 25 which a roped elevator with counterweight as shown in Fig. 10c has been replaced with or modernized into a roped elevator without counterweight according to the invention as presented in Fig. 10d. in the roped ele vator with counterweight presented in Fig. 10a, the 30 counterweight 1003 and its guide rails 1004 are placed on one side of the elevator car 1001 as seen from the door opening 1006. Fig. 10d shows how, according to the invention, the elevator in Fig. 10c has been re placed with or modernized into a roped elevator with 35 out counterweight according to the invention. The space freed up in the elevator shaft 1007 by removing WO 2004/041699 PCT/F12003/000817 35 the counterweight 1003 and its guide rails 1004 can be utilized for the elevator car 1001, allowing the width of the elevator car 1001 to be increased. In the case of a conventional passenger elevator as illustrated in 5 Fig. 10d, it is possible to obtain e.g. about 10 - 20 cm or even more of additional car width when the ele vator presented in Fig. 10c is replaced with or mod ernized into an elevator without counterweight as shown in Fig 10d. 10 Fig. 10e and 10f present a third example situation, in which a side-lifting hydraulic elevator as shown in Fig. 10e has been replaced with or modernized into an elevator without counterweight according to the inven tion as presented in Fig. 10f. The hydraulic elevator 15 in Fig. 10e comprises a hydraulic cylinder 1009 be longing to the hydraulic lifting apparatus, a divert ing pulley 1008 comprised in the hoisting rope system, and its possible guide rails are placed on one side on the elevator car 1001 as seen from the door opening 20 1006. In the situation illustrated in Fig. 10e, the elevator car 1001 is hoisted along guide rails 1002 from one side on the elevator car, but the hoisting function may also be implemented in other ways. The hydraulic lifting function to be replaced or modern 25 ized may also consist of a system with lifting force applied from below the elevator car. Fig. 10f illus trates how, according to the invention, the elevator in Fig. 10e is replaced with or modernized into a roped elevator without counterweight according to the 30 invention. The space freed up in the elevator shaft 1007 by removing the hydraulic lifting apparatus and a possible counterweight can be utilized for the eleva tor car 1001, allowing the width of the elevator car 1001 to be increased. In the case of a conventional 35 passenger elevator as illustrated in Fig. 10f, it is possible to obtain e.g. about 5 - 15 cm or even more WO 2004/041699 PCT/F12003/000817 36 of additional car width when the elevator presented in Fig. 10e is replaced with or modernized into an eleva tor without counterweight as shown in Fig 10f. It is obvious to the person skilled in the art that 5 different embodiments of the invention are not limited to the examples described above, but that they may be varied within the scope of the claims presented below. For instance, the number of times the hoisting ropes are passed between the upper part of the elevator 10 shaft and the elevator car and between the elevator car and the diverting pulleys below it is not a very decisive question as regards the basic advantages of the invention, although it is possible to achieve some additional advantages by using multiple rope passages. 15 In general, applications are so implemented that the ropes go to the elevator car from above as many times as from below, so that the suspension ratios of di verting pulleys going upwards and diverting pulleys going downwards are the same. It is also obvious that 20 the hoisting ropes need not necessarily be passed un der the car. In accordance with the examples described above, the skilled person can vary the embodiment of the invention, while the traction sheaves and rope pulleys, instead of being coated metal pulleys, may 25 also be uncoated metal pulleys or uncoated pulleys made of some other material suited to the purpose. It is further obvious to the person skilled in the art that the traction sheaves and rope pulleys of metallic or some other appropriate material that are used in 30 the invention, functioning as diverting pulleys and coated with a non-metallic material at least in the area of their grooves, may have a coating made of e.g. rubber, polyurethane or some other material suited to the purpose.

WO 2004/041699 PCT/F12003/000817 37 It is also obvious to the person skilled in the art that the elevator car and the machine unit may be laid out in the cross-section of the elevator shaft in a manner differing from the lay-out described in the ex 5 amples. Such a different lay-out might be e.g. one in which the machine is located behind the car as seen from the shaft door and the ropes are passed under the car diagonally relative to the bottom of the car. Passing the ropes under the car in a diagonal or oth 10 erwise oblique direction relative to the form of the bottom provides an advantage when the suspension of the car on the ropes is to be made symmetrical rela tive to the center of mass of the elevator in other types of suspension lay-out as well. 15 It is further obvious to the person skilled in the art that the equipment required for the supply of power to the motor and the equipment needed for elevator con trol can be placed elsewhere than in connection with the machine unit, e.g. in a separate instrument panel, 20 or equipment needed for control can be implemented as separate units which can be disposed in different places in the elevator shaft and/or in other parts of the building. It is likewise obvious to the skilled person that an elevator applying the invention may be 25 equipped differently from the examples described above. It is further obvious to the skilled person that the elevator of the invention can be implemented using almost any type of flexible hoisting means as hoisting ropes, e.g. flexible rope of one or more strands, flat 30 belt, cogged belt, trapezoidal belt or some other type of belt applicable to the purpose. It is likewise obvi ous to the skilled person that the replacement or mod ernization according to the invention of an elevator with a traction sheave elevator without counterweight 35 according to the invention can also be implemented in the case of drum elevators, screw-driven elevators or WO 2004/041699 PCT/F12003/000817 38 elevators having a hoisting function based on almost any other technique. It is also obvious to the skilled person that, instead of using ropes with a filler, the invention may be im 5 plemented using ropes without filler, which are either lubricated or unlubricated. In addition, it is also obvious to the person skilled in the art that the ropes may be twisted in many different ways. It is also obvious to the person skilled in the art 10 that the elevator of the invention can be implemented using different roping arrangements between the trac tion sheave and the diverting pulley/diverting pulleys to increase the contact angle aX than those described as examples. For example, it is possible to dispose the 15 diverting pulley/diverting pulleys, the traction sheave and the hoisting ropes in other ways than in the roping arrangements described in the examples. It is also ob vious to the skilled person that, in the elevator of the invention, the elevator may also be provided with a 20 counterweight, in which case the counterweight has e.g. a weight below that of the car and is suspended by a separate roping arrangement. Due to the bearing resistance of the rope pulleys used as diverting pulleys and to the friction between the 25 ropes and the rope sheaves and possible losses occur ring in the compensating system, the ratio between the rope tensions may deviate somewhat from the nominal ratio of the compensating system. Even a deviation of 5% will not involve any significant disadvantage be 30 cause in any case the elevator must have a certain in built robustness.

Claims

1. An elevator, comprising: an elevator car; one or more hoisting ropes; and 5 a traction sheave; wherein the elevator car is suspended by the one or more hoisting ropes, wherein the traction sheave moves the elevator car using the one or more hoisting ropes, 10 wherein the one or more hoisting ropes have rope portions going upwards and downwards from the elevator car, wherein the rope portions going upwards from the elevator car are under a first rope tension (TI), wherein the rope portions going downwards from the elevator car are 15 under a second rope tension (T 2 ), wherein the first rope tension (Ti) is greater than the second rope tension (T 2 ), wherein the elevator has been built in place of an earlier elevator mounted in an elevator shaft or by making modifications to the earlier 20 elevator, wherein a T 1 /T 2 ratio is maintained at a substantially constant value, 40 and wherein the TdT 2 ratio is independent of a load of the elevator.

2. The elevator of claim 1, wherein the elevator has been built in place of the earlier elevator. 5

3. The elevator of claim 1, wherein the elevator has been built by making modifications to the earlier elevator.

4. The elevator of claim 1, wherein the elevator is an elevator without counterweight.

5. The elevator of claim 1, further comprising: 10 a compensating mechanism; wherein the compensating mechanism is at least one of a lever, tensioning sheaves, and compensating sheaves.

6. The elevator of claim 1, further comprising: a compensating mechanism; 15 wherein the compensating mechanism comprises one or more diverting pulleys.

7. The elevator of claim 1, wherein a continuous contact angle between the traction sheave and the one or more hoisting ropes is at least 180". 20

8. The elevator of claim 1, wherein the one or more hoisting ropes include a plurality of wires, and wherein the wires have a strength greater than about 2000 N/mm 2 . 41

9. The elevator of claim 1, wherein the one or more hoisting ropes have diameters less than 8mm.

10. The elevator of claim 1, further comprising: a hoisting machine; 5 wherein the hoisting machine is lighter in weight than a nominal load of the elevator.

11. The elevator of claim 1, wherein the traction sheave is coated with at least one of a polyurethane, a rubber, and some other frictional material suited to the purpose. 10

12. The elevator of claim 1, wherein the traction sheave, at least in an area of rope grooves, is made of metal.

13. The elevator of claim 1, further comprising: a plurality of diverting pulleys; wherein a D/d ratio of the diverting pulleys below the elevator car is 15 less than 40:1, wherein D is a diameter of the diverting pulleys, and wherein d is a diameter of the one or more hoisting ropes.

14. A method for forming an elevator, in place of an earlier elevator mounted in an elevator shaft or by making modifications to the earlier 20 elevator, the method comprising: replacing a hoisting function of the earlier elevator with a hoisting function of the elevator; 42 providing one or more hoisting ropes; and arranging a traction sheave to move an elevator car of the elevator using the one or more hoisting ropes; wherein the elevator car is connected to the one or more hoisting 5 ropes so that the one or more hoisting ropes have rope portions going upwards and downwards from the elevator car, wherein the rope portions going upwards from the elevator car are under a first rope tension (TI), wherein the rope portions going downwards from the elevator car 10 are under a second rope tension (T2), wherein the elevator is provided with a compensating system for maintaining a substantially constant ratio (T 1 /T2) between the first rope tension (TI) and the second rope tension (T 2 ) and wherein the (T 1 /T 2 ) ratio is independent of a load of the elevator.

15 15- The method of claim 14, wherein the hoisting function of the formed elevator replaces a hydraulic hoisting function of the earlier elevator.

16. The method of claim 14, wherein the hoisting function of the formed elevator replaces a traction-sheave-operated hoisting function, including a counterweight, of the earlier elevator. 20

17. The method of claim 14, wherein the hoisting function of the formed elevator replaces a hoisting function, having at least one of a drum, a screw, and another corresponding hoisting function, of the earlier elevator. 43

18. The method of claim 14, wherein equipment included in the hoisting function of the earlier elevator is removed from the elevator shaft

19. The method of claim 14, wherein an elevator car of the formed elevator has a size larger than the elevator car of the earlier elevator. 5

20. The elevator of claim 1, wherein the one or more hoisting ropes having diameters greater than or equal to about 3 mm and less than or equal to about 5 mm.

21. The elevator of claim 1, wherein the traction sheave, at least in an area of rope grooves, is made of cast iron. 10

22. The elevator of claim 13, wherein the traction sheave has undercut rope grooves.